Welcome Opal and Pink Tourmaline, the two beautiful birthstones of October. These two gems form a dynamic duo as Opals showcase every color all in one, while Tourmalines can come in every color! The stacking of sub-microscopic spheres in a grid-like pattern causes a phenomenon in opals called “play of color”. The size and distance between these spheres determine the colors we see when the refracted light traveling through an opal bends, displaying its many colors. However, the color of tourmaline is specifically based on the mineral and chemical compounds, such as iron and manganese, that are found in the gemstone. The crystal structure remains the same while the mineral deposits and chemical compositions may change giving way to the vibrant colors, such as greens and pinks, that we see.